The above has been occurring on the release builds whenever all three of conditions are true:
- App is in recents
- App was last used in light mode
- App theme is set to automatic (OS)
Just to report that the problem still existed with the 20210129 (22261) Premium BETA build (apologies for being so slow to report this). I’m now going to try with the 20210215 build which is the latest on my phone.